Data processing apparatus and data processing method

ABSTRACT

The present technique relates to a data processing apparatus and a data processing method each of which enables a burden imposed on processing on a reception side to be reduced. 
     A data processing apparatus produces signaling containing a Null cell number exhibiting the number of Null cells of cells of a sub-frame included in a physical layer frame, and processes the signaling so as for the signaling to be contained in a preamble of the physical layer frame, thereby enabling a burden imposed on processing on a reception side to be reduced. The present technique, for example, can be applied to data transmission complying with the broadcasting standards such as ATSC3.0.

TECHNICAL FIELD

The present technique relates to a data processing apparatus and a dataprocessing method, and more particularly to a data processing apparatusand a data processing method each of which enables a burden imposed onprocessing on a reception side to be reduced.

BACKGROUND ART

At the present, the development of Advanced Television Systems Committee(ATSC) 3.0 as one of the next-generation terrestrial broadcastingstandards is promoted (for example, refer to NPL 1).

CITATION LIST Non Patent Literature

-   [NPL 1]-   ATSC Candidate Standard: Physical Layer Protocol (Doc. S32-230r21 28    Sep. 2015)

SUMMARY Technical Problem

Now, in the broadcasting standards such as ATSC3.0, signaling in aphysical layer (L1 signaling) is prescribed, and a reception apparatuson a reception side shall carry out demodulation processing or the likeusing this L1 signaling. On the other hand, since a burden is imposed onthe processing in the reception apparatus on the reception sidedepending on the description contents of the L1 signaling, the proposalfor reducing the burden imposed on the processing on the reception sidehas been requested.

The present technique has been made in the light of such a situation,and enables the burden imposed on the processing on the reception sideto be reduced.

Solution to Problem

A data processing apparatus of a first aspect of the present techniqueis a data processing apparatus provided with a production portion and aprocessing portion. In this case, the production portion serves toproduce signaling containing a Null cell number exhibiting the number ofNull cells of cells of a sub-frame included in a physical layer frame.The processing portion serves to execute processing so as for thesignaling to be contained in a preamble of the physical layer frame.

The data processing apparatus of the first aspect of the presenttechnique may be an independent apparatus or may be an internal blockconfiguring one apparatus. In addition, a data processing method of thefirst aspect of the present technique is a data processing methodcorresponding to the data processing apparatus of the first aspect ofthe present technique.

In the data processing apparatus and the data processing method of thefirst aspect of the present technique, the signaling containing the Nullcell number exhibiting the number of Null cells of cells of a sub-frameincluded in the physical layer frame. In addition, the signaling isprocessed so as to be contained in the preamble of the physical layerframe.

A data processing apparatus of a second aspect of the present techniqueis a data processing apparatus provided with a processing portion. Theprocessing portion serves to process signaling contained in a preambleof a physical layer frame, and containing a Null cell number exhibitingthe number of Null cells of cells of a sub-frame included in thephysical layer frame.

The data processing apparatus of the second aspect of the presenttechnique may be an independent apparatus or may be an internal blockconfiguring one apparatus. In addition, the data processing method ofthe second aspect of the present technique is a data processing methodcorresponding to the data processing apparatus of the second aspect ofthe present technique.

In the data processing apparatus and the data processing method of thesecond aspect of the present technique, the signaling contained in thepreamble of the physical layer frame, and containing the Null cellnumber exhibiting the number of Null cells of cells of a sub-frameincluded in the physical layer frame is processed.

Advantageous Effect of Invention

According to the first aspect and the second aspect of the presenttechnique, the burden imposed on the processing on the reception sidecan be reduced.

It should be noted that the effect described herein is not necessarilylimited, and thus any of the effects described in the present disclosuremay be offered.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram depicting a structure of a physical layer frame.

FIG. 2 is a diagram depicting an example of syntax of L1-basicinformation (L1-Basic).

FIG. 3 is a diagram depicting an example of syntax of L1-detailedinformation (L1-Detail).

FIG. 4 is a diagram depicting an example of syntax of the L1-detailedinformation (L1-Detail).

FIG. 5 is a diagram depicting an example of syntax of the L1-detailedinformation (L1-Detail).

FIG. 6 is a diagram explaining an outline of a Null cell number.

FIG. 7 is a diagram depicting an example of the total number of datacells.

FIG. 8 is a diagram depicting an example of the total number of datacells.

FIG. 9 is a diagram depicting the number of active data cells.

FIG. 10 is a diagram depicting the number of active data cells.

FIG. 11 is a diagram depicting the number of active data cells.

FIG. 12 is a bloc diagram depicting a configuration of a parametercontrol portion on a current reception side.

FIG. 13 is a flow chart explaining a flow of current parameter controlprocessing.

FIG. 14 is a block diagram depicting a configuration of an embodiment ofa transmission system to which the present technique is applied.

FIG. 15 is a block diagram depicting an example of a configuration of atransmission apparatus of the present technique.

FIG. 16 is a flow chart explaining a flow of modulation processing on atransmission side of the present technique.

FIG. 17 is a block diagram depicting an example of a configuration of areception apparatus of the present technique.

FIG. 18 is a flow chart explaining a flow of demodulation processing ona reception side of the present technique.

FIG. 19 is a diagram depicting an example of syntax of L1-basicinformation (L1-Basic) of the present technique.

FIG. 20 is a diagram depicting an example of syntax of the L1-basicinformation (L1-Detail) of the present technique.

FIG. 21 is a diagram depicting another example of syntax of the L1-basicinformation (L1-Basic) of the present technique.

FIG. 22 is a diagram depicting still another example of syntax of theL1-basic information (L1-Detail) of the present technique.

FIG. 23 is a blockdiagram depicting a configuration of a parametercontrol portion of the present technique.

FIG. 24 is a flow chart explaining a flow of parameter controlprocessing of the present technique.

FIG. 25 is a diagram depicting an example of Tone Reservation.

FIG. 26 is a blockdiagram depicting an example of a configuration of acomputer.

DESCRIPTION OF EMBODIMENT

Hereinafter, an embodiment of the present technique will be describedwith reference to the drawings. It should be noted that the descriptionwill be given in accordance with the following order.

1. Outline of Current Standards

2. Embodiment of the Present Technique

(1) Configuration of system

(2) Example of signaling

(3) Details of parameter control

3. Modified Changes

4. Configuration of Computer

1. <Outline of Current Standards>

(Structure of Physical Layer Frame)

FIG. 1 is a diagram depicting a structure of a physical layer frame. InFIG. 1, a transverse direction represents Time, and a longitudinaldirection represents a frequency.

For example, the physical layer frame prescribed in ATSC3.0 includes aBootstrap, a Preamble, and one or more Sub-frames. The physical layerframe is constituted by a predetermined frame length using a millimeterunit or the like. In the physical layer frame, after the bootstrap andthe preamble are acquired, the subsequent sub-frames can be acquired.

The bootstrap, for example, corresponds to a P1 symbol constituting a T2frame of Digital Video Broadcasting-Second Generation Terrestrial(DVB-T2). The preamble, for example, corresponds to a P2 symbolconstituting the T2 frame of DVB-T2. Therefore, the bootstrap can alsobe said as the preamble.

L1 signaling such as L1-basic information (L1-Basic) and L1-detailedinformation (L1-Detail) can be contained in the preamble. Here, if theL1-basic information and the L1-detailed information are compared witheach other, then, it is understood that the L1-basic information and theL1-detailed information are different in size from each other in thatalthough the L1-basic information is constituted by bits asapproximately 200 bits, the L1-detailed information is constituted by400 bits to several thousands of bits. In addition, since in thepreamble, the L1-basic information and the L1-detailed information areread out in this order, the L1-basic information is read out earlierthan the L1-detailed information. Moreover, the L1-basic information andthe L1-detailed information are also different from each other in thatthe L1-basic information is transmitted more robustly (robustness) thanthe L1-detailed information.

Payload (data) is arranged in the sub-frame. In the case where two ormore sub-frames are included in the physical layer frame, modulationparameters such as an FFT size, a guard interval length, and a pilotpattern can be changed every sub-frame.

(Structure of L1-Basic Information)

FIG. 2 is a diagram depicting an example of syntax of the L1-basicinformation (L1-Basic) contained in the preamble of FIG. 1.

L1B_content tag of 2 bits represents a tag value used to identify thecontents. L1B_version of 3 bits represents a version of the L1-basicinformation.

L1B_slt_flag of 1 bit represents whether or not Service Labeling Table(SLT) is present.

L1B_time_info_flag of 1 bit represents whether or not time informationis present. L1B_papr of 2 bits represents an application of Peak toAverage Power Reduction (PAPR).

L1B_frame_length_mode of 1 bit represents a frame mode. In the casewhere L1B_frame_length_mode=0, the frame mode becomes a time alignedmode. In addition, in the case where L1B_frame_length_mode=1, the framemode becomes a symbol aligned mode.

L1B_frame_length of 10 bits represents a frame length of the physicallayer frame. However, this L1B_frame_length is used only in the casewhere the frame mode becomes the time aligned mode, and is unused in thecase where the frame mode becomes the symbol aligned mode.

L1B number of subframes of 8 bits represents the number of sub-framesincluded in the physical layer frame. L1B preamble number of symbols of3 bits represents the number of OFDM symbols contained in the preamble.L1B_preamble_reduced_carriers of 3 bits represents the number of controlunits responding to the reduction of the maximum number of carriers eachhaving an FFT size and used in the preamble.

L1B_L1_Detail_size_bits of 16 bits represents a size of L1-detailedinformation (L1 Detail). L1B_L1_Detail_fec_type of 3 bits represents anFEC type of the L1-detailed information.L1B_L1_Detail_additional_parity_mode of 2 bits represents an additionalparity mode of the L1-detailed information. L1B_L1_Detail_total_cells of19 bits represents a total size of the L1-detailed information.

L1B_First_Sub_mimo of 1 bit represents a use situation of a MultipleInput and Multiple Output (MIMO) of the first sub-frame.L1B_First_Sub_miso of 1 bit represents a use situation of a MultipleInput and Single Output (MISO) of the first sub-frame.

L1B_First_Sub_fft_size of 2 bits represents the FFT size of the firstsub-frame.

L1B_First_Sub_reduced_carriers of 3 bits represents the number ofcontrol units responding to the reduction of the maximum number of thecarriers each having the FFT size and used in the head sub-frame.

L1B_First_Sub_guard_interval of 4 bits represents a guard intervallength of the first sub-frame.

L1B_First_Sub_excess_samples of 13 bits represents the number ofexcessive samples inserted into a guard interval portion in the (first)sub-frame. However, this L1B_First_Sub_excess_samples is used only inthe case where the frame mode becomes the time aligned mode, and isunused in the case where the frame mode becomes the symbol aligned mode.

L1B_First_Sub_num_ofdm_symbols of 11 bits represents the number of DFDMsymbols contained in the first sub-frame.

L1B_First_Sub_scattered_pilot_pattern of 5 bits represents a ScatteredPilot Pattern (SP pattern) used in the first sub-frame.

L1B_First_Sub_scattered_pilot_boost of 3 bits represents a value used toboost the size of the SP pattern.

Both L1B_First_Sub_sbs_first of 1 bit and L1B_First_Sub_sbs_last of 1bit represent a Sub-frame Boundary Symbol (SBS) of the first sub-frame.

L1B_Reserved is an area (Reserved) for future extension. Although thenumber of bits of L1B_Reserved is undetermined (TBD: To Be Determined),the number of bits of L1B_Reserved is set as 49 bits under the presentcircumstances. L1B_crc of 32 bits represents that a CRC value iscontained.

Incidentally, with regard to the L1-basic information (L1-Basic), “Table9.2 L1-Basic signaling fields and syntax” of non-patent literarydocument 1 described above describes the detailed contents of theL1-basic information (L1-Basic). In addition, the L1-basic information(L1-Basic) means that in the case where an unsigned integer mostsignificant bit first (unimsbf) is specified as the Format, a bitarithmetic operation is carried out so that the L1-basic information(L1-Basic) is treated as an integer number.

(Structure of L1-Detailed Information)

FIG. 3 to FIG. 5 are diagrams depicting examples of the syntax of theL1-detailed information (L1-Detail) contained in the preamble of FIG. 1.

L1D_version of 4 bits represents a version of the L1-detailedinformation.

A parameter regarding Channel Bonding is arranged in a loop respondingto L1D_num_rf of 3 bits. Specifically, L1D_rf_frequency of 19 bitsrepresents a frequency of RF channels bonded to each other by channelbonding.

Here, since in the case where L1B_time_info_flag=1 is obtained in theL1-basic information in FIG. 2, this exhibits that time information ispresent. Therefore, L1D_time_info as the time information is arranged inthe L1-detailed information. It should be noted that the number of bitsof L1D_time_info is to be determined (TBD).

Parameters regarding the following sub-frame are arranged in a loopresponding to L1B_num_subframes of the L1-basic information of FIG. 2.

L1D_mimo of 1 bit represents a use situation of MIMO of the sub-frame.L1D_miso of 1 bit represents a use situation of MISO of the sub-frame.L1D_fft_size of 2 bits represents an FFT size of the sub-frame.

L1D_reduced_carriers of 3 bits represents the number of control unitsresponding to the reduction of the maximum number of the carriers eachhaving the FFT size and used in the sub-frame. L1D_guard_interval of 4bits represents a guard interval length of the sub-frame.L1D_num_ofdm_symbols of 11 bits represents the number of DFDM symbolscontained in the sub-frame.

L1D_scattered_pilot_pattern of 5 bits represents an SP pattern used inthe sub-frame.

L1D_scattered_pilot_boost of 3 bits represents a value used to boost asize of the SP pattern. Both L1D_sbs_first of 1 bit and L1D_sbs_last of1 bit represent SBS of the sub-frame.

L1D_subframe_multiplex of 1 bit represents whether or not the sub-frameis adapted for time division multiplexing. L1D_frequency_interleaver of1 bit represents whether or not frequency interleave is present.

A parameter regarding PLP is arranged in a loop responding toL1D_num_plp of 6 bits. L1D_plp_id of 6 bits, L1D_plp_slt_exist of 1 bit,L1D_plp_layer of 2 bits, L1D_plp_start of 24 bits, L1D_plp_size of 24bits, L1D_plp_scrambler_type of 2 bits, L1D_plp_fec_type of 4 bits, andthe like are arranged as the parameters.

Although the whole of the parameters regarding the PLP is not describedherein, “Table 9.12 L1-Detail signaling fields and syntax” of non-patentliterary document 1 described above describes the details contents ofthe L1-detailed information (L1-Detail).

(Outline of the Number of Null Cells)

Now, in the physical layer frame prescribed in ATSC3.0, in addition toan active data cell (cell of valid data), a Null cell is contained ineach of the sub-frames. Specifically, in the case where as depicted inFIG. 6, the total number of cells within the sub-frame is set as TotalData Cells, the number of Null cells (Null Cells) is obtained bycalculating following Expression (1) by using the total number of datacells and the number of active data cells (Active Data Cells).Null Cells=Total Data Cells−Active Data Cells   (1)

It should be noted that in FIG. 6, an axis of abscissa represents afrequency, and when viewed from the whole of the total data cells, theNull cells are allocated on the ½ by ½ basis on the both sides of acenter with the active data cells as the center. In addition, in FIG. 6,it is the premise that a Sub-frame Boundary Symbol (SBS) is contained inthe sub-frame. However, the SBS is a symbol of the boundary of thesub-frame, and thus the first and last symbols of the sub-frame can eachbecome the SBS in accordance with a predetermined rule.

In the case where the number of Null cells is obtained in such a manner,it is necessary to subtract the number of active data cells from thetotal number of data cells after the total number of data cells and thenumber of active data cells are each calculated.

With regard to a method of calculating the total number of data cells, atable for calculation of the total number of data cells is previouslystored in a ROM (a ROM 312A (FIG. 12) which will be described later) ofan apparatus (reception apparatus) on the reception side. Then, thetotal number of data cells is calculated by using this table and variouskinds of control parameters of the L1 signaling. It should be noted thatthe various kinds of control parameters of the L1 signaling are obtainedfrom the preamble of the physical layer frame.

Here, as the table used in calculating the total number of data cells,for example, there are tables depicted in FIG. 7 and FIG. 8. Thesetables shall be previously stored in the ROM (the ROM 312A (FIG. 12)which will be described later) of the reception apparatus. In addition,as the various kinds of control parameters of the L1 signaling used incalculating the total number of data cells, for example, there are FFTSize, Scatter and Pilot Pattern (SPP), and Cred_coeff.

However, the various kinds of control parameters of the first sub-frameof one or more sub-frames includes in the physical layer frame aredescribed in the L1-basic information (L1-Basic), and the various kindsof control parameters of the remaining sub-frames other than the firstsub-frame are described in the L1-detailed information (L1-Detail).

Therefore, FFT Size corresponds to either L1B_First_Sub_fft_size (FIG.2) or L1D_fft_size (FIG. 3). In addition, SPP corresponds to eitherL1B_First_Sub_scattered_pilot_pattern (FIG. 2) orL1D_scattered_pilot_pattern (FIG. 3). Cred_coeff corresponds to eitherL1B_First_Sub_reduced_carriers (FIG. 2) or L1D_reduced_carriers (FIG.3).

In addition, with regard to a method of calculating the number of activedata cells, a table for calculation of the number of active data cellsis previously stored in a ROM (a ROM 313A (FIG. 12) which will bedescribed later) of the reception apparatus on the reception side. Then,the number of active data cells is calculated by using this table andvarious kinds of control parameters of the L1 signaling.

Here, as the table used in calculating the number of active data cells,for example, there are tables depicted in FIG. 9 to FIG. 11. Thesetables shall be previously stored in the ROM (the ROM 313A FIG. 12)) ofthe reception apparatus. In addition, as the various kinds of controlparameters of the L1 signaling used in calculating the number of activedata cells, for example, there are FFT Size, SPP, Cred_coeff, SPBoost,and PAPR.

As described above, FFT Size corresponds to eitherL1B_First_Sub_fft_size (FIG. 2) or L1D_fft_size (FIG. 3). In addition,SPP corresponds to either L1B_First_Sub_scattered_pilot_pattern (FIG. 2)or L1D_scattered_pilot_pattern (FIG. 3). Cred_coeff corresponds toeither L1B_First_Sub_reduced_carriers (FIG. 2) or L1D_reduced_carriers(FIG. 3). In addition, SPBoost corresponds to eitherL1B_First_Sub_scattered_pilot_boost (FIG. 2) orL1D_scattered_pilot_boost (FIG. 3). PAPR corresponds to L1B_papr (FIG.2).

For example, in the case where FFT Size as “16K”, SPP as “SP32_4”,Cred_coeff as “4”, and SPBoost as “4” are deciphered as various kinds ofcontrol parameters of the L1 signaling, 12558 is calculated (frame A ofFIG. 8) as the total number of data cells, and 10622 is calculated(frame B of FIG. 10) as the number of active data cells. Then,Expression (1) described above is applied to the total number of datacells and the number of active data cells which are obtained in such amanner, thereby obtaining the number of Null cells as 1966(=12588−10622).

(Configuration of Parameter Control Portion on Current Reception Side)

Next, a description will now be given with respect to a configuration ofthe reception apparatus responding to the current standards. In thiscase, however, in order to simplify the description, the description ofa quadrature demodulation portion, an OFDM reception portion, adeinterleaving portion and the like configuring the reception apparatusconcerned is omitted, and the description is given with a focus on aconfiguration of a parameter control portion 301 (FIG. 12) forprocessing the L1 signaling.

FIG. 12 is a blockdiagram depicting the configuration of the parametercontrol portion 301 on the current reception side.

In FIG. 12, the parameter control portion 301 on the current receptionside is configured to include a signaling decoding portion 311, a totaldata cell number calculating portion 312, an active data cell numbercalculating portion 313, and a Null sell number calculating portion 314.

The signaling decoding portion 311 decodes data inputted thereto aftererror correction (reception L1 series) in accordance with apredetermined decoding system, thereby deciphering the various kinds ofcontrol parameters of the L1 signaling. The signaling decoding portion311 supplies FFT Size, SPP, and Cred_coeff of the various kinds ofcontrol parameters thus deciphered to the total data cell numbercalculating portion 312, and also supplies FFT Size, SPP, Cred_coeff,SPBoost, and PAPR of the various kinds of control parameters thusdeciphered to the active data cell number calculating portion 313.

The total data cell number calculating portion 312 reads out a table forcalculation of the total number of data cells from the ROM 312A providedin the inside thereof, and calculates the total number of data cellsresponding to FFT Size, SPP, and Cred_coeff by using the tableconcerned. The total number of data cells is supplied to the Null cellnumber calculating portion 314. In addition, the total number of datacells, for example, is supplied to each of the portions of the receptionapparatus, for example, the OFDM reception portion and the likeutilizing the total number of data cells as the control parameter.

The active data cell number calculating portion 313 reads out a tablefor calculation of the number of active data cells from the ROM 313Aprovided in the inside thereof, and calculates the number of active datacells responding to FFT Size, SPP, Cred_coeff, SPBoost, and PAPR byusing this table concerned. The number of active data cells is suppliedto the Null cell number calculating portion 314.

The total number of data cells from the total data cell numbercalculating portion 312 and the number of active data cells from theactive data cell number calculating portion 313 are both supplied to theNull cell number calculating portion 314. The Null cell numbercalculating portion 314 subtracts the number of active data cells fromthe total number of data cells by applying Expression (1) describedabove, thereby calculating the number of Null cells. The number of Nullcells is supplied to each of the portions of the reception apparatus,for example, the frequency deinterleaving portion and the like, whichutilize the number of Null cells as the control parameter.

(Flow of Current Parameter Control Processing)

Next, a description will now be given with respect to a flow of currentparameter control processing which is executed by the parameter controlportion 301 of FIG. 12 with reference to a flow chart of FIG. 13.

In Step S301, the signaling decoding portion 311 receives as an inputthereof the data (reception L1 series) after the error correction. Inaddition, in Step S302, the signaling decoding portion 311 decodes thedata (reception L1 series) after the error correction inputted theretoin the processing of Step S301 in accordance with the predetermineddecoding system, thereby deciphering the various kinds of controlparameters (FFT Size, SPP, Cred_coeff, SPBoost, and PAPR) of the L1signaling.

In Step S303, the total data cell number calculating portion 312calculates the total number of data cells responding to FFT Size, SPP,and Cred_coeff which are deciphered in the processing of Step S302 byusing the table (for example, the table of FIG. 7 and FIG. 8) forcalculation of the total number of data cells stored in the ROM 312A.

In Step S304, the active data cell number calculating portion 313calculates the number of active data cells responding to FFT Size, SPP,Cred_coeff, SPBoost, and PAPR which are deciphered in the processing ofStep S302 by using the table (for example, the table of FIG. 9 to FIG.11) for calculation of the number of active data cells stored in the ROM313A.

In Step S305, the Null cell number calculating portion 314 subtracts thenumber of active data cells from the total number of data cells byapplying Expression (1) described above to the total number of datacells calculated in the processing of Step S303, and the number ofactive data cells calculated in the processing of Step S304, therebycalculating the number of Null cells.

In Step S306, the Null cell number calculating portion 314 supplies thenumber of Null cells calculated in the processing of Step S305 to thefrequency deinterleaving portion. Then, when the processing of Step S306is ended, the current parameter control processing of FIG. 13 is endedaccordingly.

As described above, in the current parameter control processing, thetotal number of data cells and the number of active data cells arecalculated by using the table (for example, the table of FIG. 7 and FIG.8, the Table of FIG. 9 to FIG. 11, or the like) previously stored in theROM, and the various kinds of control parameters (for example, FFT Size,SPP, Cred_coeff, SPBoost, and PAPR) of the deciphered L1 signaling. Inaddition, the number of Null cells is obtained by applying Expression(1) described above to the total number of data cells and the number ofactive data cells which are calculated in the manner as described above.

However, in the current reception apparatus, in order to calculate thenumber of Null cells by using Expression (1) described above, it wasnecessary to calculate the total number of data cells and the number ofactive data cells by using the table and the various kinds of controlparameters. This calculation processing became a burden imposed on thereception apparatus. In addition, in the current reception apparatus,the multiple tables (for example, the table of FIG. 7 and FIG. 8, thetable of FIG. 9 to FIG. 11, and the like) used to calculate the totalnumber of data cells and the number of active data cells needed to bepreviously stored in the ROM (for example, the ROM 312A or the ROM 313Aof FIG. 12, or the like). In order to attain this, a large storagecapacity must be secured in the ROM, which was a burden imposed on thereception apparatus.

In such a manner, in the current standards, it was necessary to providean arithmetic operation circuit, a memory and the like for calculatingthe number of Null cells. As a result, the burden imposed on thereception apparatus was increased. Then, in the present technique, thenumber of Null cells is not calculated in the reception apparatus on thereception side, but the number of Null cells is transmitted so as toinclude the L1 signaling, thereby enabling the burden imposed on thereception apparatus resulting from the number of Null cells, therebyenabling the burden imposed on the reception apparatus resulting fromthe number of Null cells to be reduced. Hereinafter, a description willbe given with respect to a transmission system to which such a presenttechnique is applied.

2. <Embodiment of the Present Technique>

(1) Configuration of System

(Example of Configuration of Transmission System)

FIG. 14 is a block diagram depicting a configuration of an embodiment ofthe transmission system to which the present technique is applied. Itshould be noted that the system means one in which a plurality ofapparatuses is logically gathered together.

In FIG. 14, the transmission system 1 is configured to include atransmission apparatus 10 and a reception apparatus 20. In thistransmission system 1, the data transmission complying with thestandards of the digital broadcasting such as ATSC3.0 is carried out.

Incidentally, in ATSC3.0 as one of the next-generation terrestrialbroadcasting standards, it is supposed that a system of not using aTransport Stream (ST) packet, but mainly using an Internet Protocol (IP)packet including an IP/UDP packet, that is, a User Datagram Protocol(UDP) packet is adapted in the data transmission. In addition, even inthe broadcasting system other than ATSC3.0, it is expected that in thefuture, a system using the IP packet will be adopted.

The transmission apparatus 10 transmits contents through a transmissionpath 40. For example, the transmission apparatus 10 transmits abroadcasting stream containing (a component of) the video, the audio andthe like constituting the contents of a broadcasting program or thelike, and the signaling as a digital broadcasting signal through thetransmission path 40.

The reception apparatus 20 receives the contents transmitted theretofrom the transmission apparatus 10 through the transmission path 40, andoutputs the contents thus received. For example, the reception apparatus20 receives the digital broadcasting signal from the transmissionapparatus 10, acquires (the component of) the video, the audio, and thelike constituting the contents, and the signaling from the broadcastingstream, and reproduces the video and audio of the contents of thebroadcasting program or the like.

Incidentally, although in the transmission system 1 of FIG. 14, in orderto simplify the description, only one reception apparatus 20 isillustrated, a plurality of reception apparatuses 20 can be provided. Inthis case, the digital broadcasting signal which the transmissionapparatus 10 transmits (simultaneous broadcasting) can be simultaneouslyreceived by a plurality of reception apparatuses 20 through thetransmission path 40.

In addition, in the transmission system 1 of FIG. 14, a plurality oftransmission apparatuses 10 can also be provided. A plurality oftransmission apparatuses 10 can transmit the digital broadcastingsignals containing the broadcasting stream with, for example, differentfrequency bands as different channels, and the reception apparatus 20can select a channel, with which the broadcasting stream is received,from the channels of a plurality of transmission apparatuses 10.

Moreover, in the transmission system 1 of FIG. 14, the transmission path40 may be adapted for, for example, the satellite broadcasting utilizingthe Broadcasting Satellite (BS) or a Communication Satellite (CS), thecable broadcasting (CATV) using the cable, or the like in addition tothe territorial broadcasting signal (territorial broadcasting).

(Example of Configuration of Transmission Apparatus)

FIG. 15 is a block diagram depicting an example of a configuration ofthe transmission apparatus 10 in FIG. 14.

In FIG. 15, the transmission apparatus 10 is configured to include anencoder portion 111, a parameter control portion 112, an errorcorrection encoding portion 113, a time interleaving portion 114, afrequency interleaving portion 115, an OFDM transmitting portion 116, aquadrature modulation portion 117, and an RF analog portion 118.

The encoder portion 111 encodes the data (of the sub-frame) inputtedthereto from a circuit (not depicted) in a preceding stage, and suppliesthe encoded data to the error correction encoding portion 113.

The parameter control portion 112 produces the data of the L1 signaling(preamble) containing the various kinds of control parameters, andsupplies the resulting data to the error correction encoding portion113. For example, the L1-basic information (L1-Basic), the L1-detailedinformation (L1-Detail), and the like are produced as the L1 signaling.In addition, the number of Null cells (L1B_First_Sub_sbs_null_cells FIG.19) or L1D_sbs_null_cell (FIG. 20) which will be described later) iscontained as the control parameter in the L1 signaling.

The error correction analog portion 113 executes error encodingprocessing (for example, BCH encoding, Low Density Check (LDPC) encodingor the like) for the data supplied thereto from the encoder portion 111and the preamble control portion 112. The error correction encodingportion 113 supplies the data after the error correction encoding to thetime interleaving portion 114.

The time interleaving portion 114 carries out the interleave in the timedirection for the data supplied thereto from the error correctionencoding portion 113, and supplies the data after the interleave in thetime direction to the frequency interleaving portion 115.

The frequency interleaving portion 115 carries out the interleave in thefrequency direction for the data supplied thereto from the timeinterleaving portion 114, and supplies the data after the interleave inthe frequency direction to the OFDM transmission portion 116.

The OFDM transmission portion 116 carries out Inverse Fast FourierTransform (IFFT) arithmetic operation for the data supplied thereto fromthe frequency interleaving portion 115, and supplies the resultingOrthogonal Frequency Division Multiplexing (OFDM) signal to thequadrature modulation portion 117. It should be noted that the signalingof the bootstrap is contained in the OFDM signal.

The quadrature modulation portion 117 subjects the OFDM signal of thebase band supplied thereto from the OFDM transmission portion 116 to thequadrature modulation, and supplies the resulting signal to theRF⋅analog portion 118. It should be noted that after Digital/Analog(D/A) conversion processing is executed for the signal processed in thequadrature modulation portion 117 to convert the digital signal into ananalog signal, the resulting analog signal is inputted to the RF analogportion 118.

The RF analog portion 118 is connected to an antenna 101 and convertsthe signal supplied thereto from the quadrature modulation portion 117into a Radio Frequency (RF) signal, and transmits the resulting RFsignal to the reception apparatus 20 through the transmission path 40.

(Flow of Modulation Processing on Transmission Side of the PresentTechnique)

Next, a description will now be given with respect to a flow of themodulation processing, on the transmission side of the presenttechnique, which is executed by the transmission apparatus 10 of FIG.14. Incidentally, a description of FIG. 16 will be given with a focus onprocessing executed by the parameter control portion 112 and the OFDMtransmission portion 116.

In Step S101, the OFDM transmission portion 116 modulates the sub-frame(sub-frame symbol).

Incidentally, although the detailed description is omitted herein, theerror correction encoding processing is executed for the data obtainedby the encoding in the encoder portion 111 by the error correctionencoding portion 113. Thereafter, the data obtained by carrying out theinterleave in the time direction and in the frequency direction by thetime interleaving portion 114 and the frequency interleaving portion 115is modulated as the sub-frame by the OFDM transmission portion 116.

In Step S102, the parameter control portion 112 produces the dataassociated with the L1 signaling (preamble) containing the various kindsof control parameters. For, example, the L1-basic information(L1-Basic), the L1-detailed information (L1-Detail), and the like areproduced as the L1 signaling. In addition, the number of Null cells(L1B_First_Sub_sbs_null_cells (FIG. 19) or L1D_sbs_null_cells (FIG. 20)which will be described later) is contained as the control parameter inthe L1 signaling.

Incidentally, although the detailed description is omitted herein, theerror correction encoding processing is executed for the data associatedwith the L1 signaling which is produced in the processing by the errorcorrection encoding portion 113 in Step S102. Thereafter, the interleavein the time direction and the interleave in the frequency direction areeach carried out by the time interleaving portion 114 and the frequencyinterleaving portion 115.

In Step S103, the OFDM transmission portion 116 modulates a preamblesymbol of the L1 signaling produced in the processing of Step S102.

In Step S104, the OFDM transmission portion 116 produces the signalingof the bootstrap containing the control parameters.

In Step S105, the OFDM transmission portion 116 modulates the signalingof the bootstrap produced in the processing in Step S104.

In Step S106, it is decided whether or not the processing should beended. In the case where it is decided in Step S106 that the processingshould not be ended, the processing is returned back to Step S101. Then,the pieces of processing Step S101 to Step S105 described above arerepetitively executed with a next physical layer frame as the processingtarget.

On the other hand, in the case where it is decided in Step S106 that theprocessing should be ended, the modulation processing on thetransmission side of the present technique of FIG. 16 is ended.

The flow of the modulation processing on the transmission side of thepresent technique has been described so far. In the modulationprocessing on the transmission side of the present technique, inaddition to FFT Size, SPP, Cred_coeff, and the like, the number of Nullcells is also produced as the various kinds of control parameters, andis transmitted so as to be contained in the L1 signaling (preamble).

(Example of Configuration of Reception Apparatus)

FIG. 17 is block diagram depicting an example of a configuration of thereception apparatus 20 of FIG. 14.

In FIG. 17, the reception apparatus 20 is configured to include an RFanalog portion 211, a quadrature demodulation portion 212, an OFDMreceiving portion 213, a frequency interleaving portion 214, a timeinterleaving portion 215, an error correction decoding portion 216, aparameter control portion 217, and a decoder portion 218.

The RF analog portion 211 is connected to an antenna 201, and receivesthe RF signal transmitted thereto from the transmission apparatus 10through the transmission path 40. The RF analog portion 211 processesthe RF signal and supplies the resulting signal to the quadraturedemodulation portion 212. Incidentally, after the signal obtained by theprocessing in the RF⋅analog portion 211 is subjected to Analog/Digital(A/D) conversion processing to be converted from the analog signal intothe digital signal, the resulting digital signal is inputted to thequadrature demodulation portion 212.

The quadrature demodulation portion 212 subjects the signal suppliedthereto from the RF analog portion 211 to the quadrature demodulation,and supplies the resulting OFDM signal of the base band to the OFDMreceiving portion 213.

The OFDM receiving portion 213 carries out the Fast Fourier Transform(FFT) arithmetic operation for the OFDM signal supplied thereto from thequadrature demodulation portion 212, extracts the dataquadrature-demodulated to the subcarriers, and supplies the dataconcerned to the frequency deinterleaving portion 214.

The frequency deinterleaving portion 214 carries out the deinterleave inthe frequency direction for the data supplied thereto from the OFDMreceiving portion 213, and supplies the data after the deinterleave inthe frequency direction to the time deinterleaving portion 215.

The time deinterleaving portion 215 carries out the deinterleave in thetime direction for the data supplied thereto from the frequencydemodulating portion 214, and supplies the data after the deinterleavein the time direction to the error converting decoding portion 216.

The error converting decoding portion 216 executes the error correctionprocessing (for example, the LDPC decoding, the BCH decoding or thelike) for the data supplied thereto from the time deinterleaving portion215. The error correction decoding portion 216 supplies the dataassociated with the preamble of the pieces of data after the errorcorrection to the parameter control portion 217, and supplies the dataassociated with the sub-frame to the decoder portion 218.

The parameter control portion 217 processes the data supplied theretofrom the error correction decoding portion 216, and supplies the variouskinds of control parameters contained in the L1 signaling to each of theportions of the reception apparatus 20. It should be noted that thedetailed configuration of the parameter control portion 217 will bedescribed later with reference to FIG. 23.

For example, the parameter control portion 217 supplies the number ofNull cells (L1B_First_Sub_sbs_null_cells (FIG. 19) or L1D_sbs_null_cells(FIG. 20) which will be described later) which is contained in the L1signaling to the frequency deinterleaving portion 214. As a result, thefrequency deinterleaving portion 214 carries out the deinterleave in thefrequency direction for the active data associated with the portionexcept for the Null cells in response to the number of Null cells fromthe parameter control portion 217.

The decoder portion 218 decodes the data (of the sub-frame) suppliedthereto from the error correction decoding portion 216, and outputs theresulting data to a circuit (not depicted) in a subsequent stage.

(Flow of Decoding Processing on Reception Side of the Present Technique)

Next, FIG. 18 describes a flow of the decoding processing, on thereception side of the present technique, which is executed by thereception apparatus 20 of FIG. 14. However, a description of FIG. 18will be given with a focus on the processing which is executed by theOFDM receiving portion 213, and the parameter control portion 217.

In Step S201, the OFDM receiving portion 213 detects the bootstrap ofthe physical layer frame. Here, in the case where the OFDM receivingportion 213 detects the bootstrap, OFDM receiving portion 213 carriesout the correlated calculation of the time domain for the OFDM signal ofthe base band, and detects a position where the autocorrelation becomesmaximum as a trigger position of the bootstrap.

In Step S202, the OFDM receiving portion 213 executes the equalizationprocessing for the bootstrap detected in the processing of Step S201,and demodulates the bootstrap.

In Step S203, the OFDM receiving portion 213 deciphers (decodes) thesignaling of the bootstrap demodulated in the processing of Step S202,and carries out the parameter control using the resulting controlparameters.

In Step S204, the OFDM receiving portion 213 executes the equalizationprocessing for the preamble symbol in accordance with the parametercontrol for the processing of Step S203, and demodulates the preamblesymbol.

Incidentally, although the detailed description is omitted herein, thefrequency deinterleaving portion 214 and the time deinterleaving portion215 execute the deinterleave in the frequency direction and thedeinterleave in the time direction, respectively, for the preamblesymbol demodulated in the processing of Step S204. Thereafter, the errorcorrection decoding portion 216 executes the error correction decodingprocessing for the preamble symbol demodulated in the processing of StepS204.

In Step S205, the parameter control portion 217 deciphers (decodes) theL1 signaling contained in the preamble which is obtained in theprocessing or the like of Step S204, and carries out the parametercontrol using the various kinds of resulting control parameters.

For example, the parameter control portion 217 supplies the number ofNull cells (L1B_First_Sub_abs_null_cells (FIG. 19) or L1D_sbs_null_cells(FIG. 20) which will be described later) contained in the L1 signalingto the frequency deinterleaving portion 214. As a result, the frequencydeinterleaving portion 214 carries out the deinterleave in the frequencydirection for the active data associated with a portion except for thenumber of Null cells in response to the number of Null cells from theparameter control portion 217.

In Step S206, the OFDM receiving portion 213 executes the equalizationprocessing for the sub-frame (sub-frame symbol) in accordance with theparameter control for the processing of Step S205, and demodulates thesub-frame.

Incidentally, although the detailed description is omitted herein, thefrequency deinterleaving portion 214 and the time deinterleaving portion215 execute the deinterleave in the frequency direction and thedeinterleave in the time direction, respectively, for the sub-framewhich is demodulated in the processing of Step S206. Thereafter, theerror correction decoding portion 216 executes the error correctiondecoding processing for the sub-frame demodulated in the processing ofStep S206. Then, the decoder portion 218 decodes the data (of thesub-frame) obtained in the processing or the like of Step S206, andoutputs the resulting data.

In Step S207, it is decided whether or not the processing should beended. In the case where it is decided in Step S207 that the processingshould not be ended, the processing is returned back to Step S202. Then,the pieces of processing Steps S202 to S206 described above arerepetitively executed with a next physical frame as a processing target.

On the other hand, in the case where it is decided in Step S207 that theprocessing should be ended, the decoding processing on the receptionside of the present technique of FIG. 18 is ended.

The flow of the demodulation processing on the reception side of thepresent technique has been described so far. In the demodulationprocessing in the reception side of the present technique, the number ofNull cells can be acquired together with FFT Size, SPP, Cred_coeff, andthe like as the various kinds of control parameters which aretransmitted so as to be contained in the L1 signaling (preamble).Therefore, it is unnecessary to provide an arithmetic operation circuit,a memory, and the like for calculating the number of Null cells, andthus the burden imposed on the reception apparatus can be reduced.

(2) Example of Signaling

(Structure of L1-Basic Information)

FIG. 19 is a diagram depicting an example of syntax of L1-basicinformation (L1-Basic) of the present technique.

Although in FIG. 19, the description is given with a part of theL1-basic information being extracted, the L1-basic information of FIG.19 is different from the L1-basic information of FIG. 2 in that thefield of L1B_First_Sub_sbs_null_cells of 11 bits is added (thick lettersin the figure). This L1B_First_Sub_sbs_null_cells represents the numberof Null cells of the first sub-frame.

It should be noted that although the number of bits ofL1B_First_Sub_sbs_null_cells is set as 11 bits in this case, the othernumber of bits may be set depending on the operation.

(Structure of L1-Detailed Information)

FIG. 20 is a diagram depicting an example of the syntax of theL1-detailed information (L1-Detail) of the present technique.

Although in FIG. 20, the description is given with a part of theL1-detailed information being extracted, the L1-detailed information ofFIG. 20 is difficult from the L1-detailed information of FIG. 3 to FIG.5 in that the field of L1D_sbs_null_cells of 11 bits is added (thickletters in the figure). This L1D_sbs_null_cells represents the number ofNull cells of the remaining sub-frames other than the first sub-frame.

It should be noted that although the number of bits ofL1D_sbs_null_cells is set as 11 bits in this case, the other number ofbits may be set depending on the operation.

Here, with regard to a description method for the number of Null cells,other description methods other than the description methods depicted inFIG. 19 and FIG. 20 may be adopted. For example, as depicted in FIG. 6described above, in each of the sub-frames, the Null cells are allocatedto the both ends on ½-by-½ basis with the active data cell as thecenter. The half of the number of Null cells (number of ½) may bedescribed in the L1 signaling by utilizing this relationship. Then,next, a description will be given with respect to the case where thehalf of the number of Null cells (number of ½) is described in theL1-basic information and the L1-detailed information with reference toFIG. 21 and FIG. 22.

(Another Structure of L1-Basic Information)

FIG. 21 is a diagram depicting another example of the syntax of theL1-basic information (L1-Basic) of the present technique.

Although the L1-basic information is described in FIG. 21 with a partthereof being extracted, the L1-basic information of FIG. 21 isdifferent from the L1-basic information of I. in that the field ofL1B_First_Sub_sbs_active_carrier_start of 10 bits is added (thickletters in the figure). This L1B_First_Sub_sbs_active_carrier_startrepresents the half of the number of Null cells (number of ½) of thefirst sub-frame.

Here, the number of bits of L1B_First_Sub_sbs_active_carrier_start is 10bits. Thus, the half of the number of Null cells is described, therebyresulting in that as compared with the case ofL1B_First_Sub_sbs_null_cells of 11 bits in which the whole of the numberof Null cells is described (FIG. 19), the number of bits of 1 bit can bereduced. It should be noted that although the number of bits ofL1B_First_Sub_sbs_null_cells is set as 10 bits, the other number of bitsmay be set depending on the operation.

(Another Structure of L1-Detailed Information)

FIG. 22 is a diagram depicting another example of syntax of theL1-detailed information (L1-Detail) of the present technique.

Although the L1-detailed information is described in FIG. 22 with a partthereof being extracted, the L1-detailed information of FIG. 22 isdifferent from the L1-detailed information of FIG. 3 to FIG. 5 in thatthe field of L1D-sbs_active_carrier_start of 10 bits is added (thickletters in the figure). This L1D-Sbs_active_carrier_start represents thehalf (number of ½) of the number of Null cells of the remainingsub-frames other than the first sub-frame.

Here, the number of bits of L1D-sbs_active_carrier_start is 10 bits.Thus, the half of the number of Null cells is described, therebyresulting in that as compared with the case of L1D_sbs_null_cells (FIG.20), the number of bits as 1 bit can be reduced. It should be noted thatalthough the number of bits of L1D-sbs_active_carrier_start is set as 10bits, the other number of bits may be set depending on the operation.

It should be noted that although in FIG. 19 to FIG. 22, the descriptionhas been given with respect to the case where the number of Null cellsor the half (number of ½) of the number of Null cells is described inthe L1 signaling, the number which should be described in the L1signaling is by no means limited to the number of Null cells and, forexample, the number of active data cells may be described.

Specifically, it is supposed that in the parameter control portions 217,in order to output (present) the total number of data cells to each ofthe portions (for example, the OFDM receiving portion 213 and the like)of the reception apparatus 20 (FIG. 17), the table for calculation forthe total number of data cells is held. In this case, however, the tablefor calculation for the total number of data cells is used, therebyresulting in that the total number of data cells responding to FFT Size,SPP, Cred_coeff can be calculated.

Then, the number of active data cells is transmitted so as to becontained in the L1 signaling, thereby resulting in that if Expression(1) described above is calculated, then, the number of active data cellswhich is deciphered from the L1 signaling is subtracted from the totalnumber of data cells which are calculated by using the table forcalculation of the total number of data cell to enable the number ofNull cells to be obtained. It should be noted that even in this case,since the parameter control portion 217 does not need to calculate thenumber of active data cells, and to hold the table for calculation ofthe number of active data cells, it is unchanged that the burden imposedon the reception apparatus can be reduced.

(3) Details of Parameter Control

Next, a description will be given with respect to the details of theparameter control portion by the parameter control portion 217 in thecase where the L1-basic information (L1-Basic) of FIG. 19, and theL1-detailed information (L1-Detail) of FIG. 20 are transmitted as the L1signaling.

(Configuration of Parameter Control Portion of the Present Technique)

FIG. 23 is a blockdiagram depicting a configuration of the parametercontrol portion 217 of FIG. 17.

In FIG. 23, the parameter control portion 217 is configured to include asignaling decoding portion 221 and a total data cell number calculatingportion 222.

The signaling decoding portion 221 decodes the data (reception L1series) after the error correction which is supplied thereto from theerror correction decoding portion 216 (FIG. 17) in accordance with apredetermined decoding system, thereby deciphering the various kinds ofcontrol parameters of the L1 signaling.

The signaling decoding portion 221 outputs the number of Null cells (forexample, L1B_First_Sub_sbs_null_cells of FIG. 19 or L1D_sbs_null_cellsof FIG. 20) of the various kinds of deciphered control parameters to thefrequency deinterleaving portion 214 (FIG. 17). Incidentally, adestination of the output of the number of Null cells as the controlparameters is by no means limited to the frequency deinterleavingportion 214, but is supplied to each of the portions of the receptionapparatus 20 (FIG. 17) utilizing the number of Null cells concerned.

In addition, the signaling decoding portion 221 supplies FFT Size, SPP,Cred_coeff of the various kinds of deciphered control parameters to thetotal data cell number calculating portion 222.

The total data cell number calculating portion 222 reads out the tablefor calculation of the total number of data cells from the ROM 222provided in the inside thereof, and calculates the total number of datacells responding to FFT Size, SPP, Cred_coeff by using the tableconcerned. The total number of data cells is supplied to each of theportions of the reception apparatus 20 (FIG. 17), for example, the OFDMreceiving portion 213 (FIG. 17) and the like, which utilize the totalnumber of data cells as the control parameter.

It should be noted that although the illustration is omitted in FIG. 23,the various kinds of control parameters depicted by the signalingdecoding portion 221 shall be supplied to each of the portions of thereception apparatus 20 (FIG. 17) which utilize the various kinds ofcontrol parameters concerned.

(Flow of Parameter Control Processing of the Present Technique)

Next, a description will be given with respect to a flow of parametercontrol processing which is executed by the parameter control portion217 of FIG. 17 with reference to a flow chart of FIG. 24. However, thedescription of FIG. 24 will now be given with a focus on the processingregarding the number of Null cells of the various kinds of controlparameters of the L1 signaling.

In Step S221, the signaling decoding portion 221 receives as an inputthereof the data after the error correction (reception L1 series) fromthe error correction decoding portion 216 (FIG. 17).

In Step S222, the signaling decoding portion 221 decodes the data afterthe error correction (reception L1 series) inputted thereto in theprocessing of Step S221 in accordance with a predetermined decodingsystem, thereby deciphering the various kinds of control parameters (thenumber of Null cells) of the L1 signaling. As far as the number of Nullcells, for example, L1B_First_Sub_sbs_null_cells of FIG. 19 orL1D_sbs_null_cells of FIG. 20 is deciphered.

In Step S223, the signaling decoding portion 221 outputs the number ofNull cells deciphered in the processing of Step S222 to the frequencydeinterleaving portion 214 (FIG. 17). Then, when the processing of StepS223 is ended, the parameter control processing of the present techniqueof FIG. 24 is ended accordingly.

It should be noted that although in the parameter control processing ofFIG. 24, the description has been given with a focus on the processingregarding the number of Null cells of the various kinds of controlparameters of the L1 signaling, other control parameters are alsodeciphered to be processed. For example, FFT Size, SPP, Cred_coeff aredeciphered by the signaling decoding portions 221, thereby resulting inthat the total data cell number calculating portion 222 calculates thetotal number of data cells responding to FFT Size, SPP, Cred_coeff byusing the table (for example, the table of FIG. 7 and FIG. 8, or thelike) for calculation of the total number of data cells of the ROM 222A,and outputs the total number of data cells.

The flow of the parameter control processing of the present techniquehas been described so far. Since in the parameter control processing ofthe present technique, the number of Null cells is transmitted so as tobe contained in the L1 signaling, it is unnecessary to calculate thenumber of Null cells by using the total number of data cells and thenumber of active data cells. In addition, the number of Null cellscontained in the L1 signaling is deciphered, thereby resulting in thatthe number of Null cells is acquired and outputted.

For this reason, for calculating the number of Null cells, it isunnecessary to calculate the total number of data cells and the numberof active data cells by using the table stored in the ROM, and thevarious kinds of control parameters. Therefore, the burden imposed onthe reception apparatus 20 by this calculation processing can bereduced. In addition, the multiple tables (for example, the tables ofFIG. 9 to FIG. 11, and the like) used for calculating the number ofcells such as the number of active data cells do not need to be storedin the ROM in advance. Therefore, a large storage capacity does not needto be secured in the ROM, and thus the burden imposed on the receptionapparatus 20 can be reduced.

In such a way, in the present technique, the number of Null cells istransmitted so as to be contained in the L1 signaling, thereby resultingin that the arithmetic operation circuit, the memory and the like forcalculation of the number of Null cells do not need to be provided. As aresult, the burden imposed on the reception apparatus resulting from thenumber of Null cells can be reduced.

Incidentally, Tone Reservation is not taken into consideration in thetable (for example, the table depicted in FIG. 7 and FIG. 8) forcalculation of the total number of data cells described above, or thetables (for example, the tables depicted in FIG. 9 to FIG. 11) forcalculation of the number of active data cells. If up to the tonereservation is taken into consideration, then, it is possible that thenumber of tables for calculation of the number of cells is furtherincreased.

Here, the tone reservation is such that for the purpose of reducing thevalue of PAPR, a special signal is inserted into the carrier and, forexample, is adopted in DVB-T2. FIG. 25 depicts an example of a carrierindex of the tone reservation. For example, in the case where, forexample, the tone reservation is taken into consideration, it is alsosupposed that the number of tables which is approximately twice thenumber of current tables is required.

<3. Modified Changes>

Although the description has been given with respect to ATSC(especially, ATSC3.0) as the system adopted in U.S.A. and the like, thepresent technique may also be applied to Integrated Services DigitalBroadcasting (ISDB) as the system adopted in Japan and the like, DigitalVideo Broadcasting (DVB) as the system adopted in the countries ofEurope and the like, or the like. In addition, although the abovedescription has been given with ATSC3.0 in which the IP transmissionsystem is adopted as an example, the present technique is by no meanslimited to the IP transmission system, and may also be applied to othersystems, for example, MPEG-Transport Stream (TS) system or the like.

In addition, as far as the digital broadcasting, the present techniquecan be applied to the satellite broadcasting utilizing the broadcastingsatellite (BS), the communication satellite (CS) or the like, the cablebroadcasting such as the cable television (CATV) or the like in additionto the terrestrial broadcasting. Moreover, the name of (the field of)the signaling described above is merely an example, and other name isused in some cases instead. For example, such other name as to mean “thenumber of Null cells” may be used in L1B_First_Sub_sbs_null_cells ofFIG. 19 or L1D_sbs_null_cells of FIG. 20. However, the difference inthese names is the formal difference, and the substantial contents suchas (the field of) the signaling as the object are not different.

In addition, the present technique can also be applied to thepredetermined standards (the standards other than the standards of thedigital broadcasting) prescribed on the assumption that the transmissionpath other than the broadcasting network, that is, for example, theInternet or the communication line (communication network) such as thetelephone network is utilized as the transmission path. In this case,the Internet or the communication line such as the telephone network isutilized as the transmission path 40 of the transmission system 1 (FIG.14), and thus the transmission apparatus 10 can be made a serverprovided on the Internet. Then, the reception apparatus 20 is adapted tohave a communication function, whereby the transmission apparatus 10(server) execute the processing in response to a request made from thereception apparatus 20. On the other hand, the reception apparatus 20shall process the data which is transmitted thereto from thetransmission apparatus 10 (server) through the transmission path 40(communication line).

<4. Configuration of Computer>

The series of pieces of processing described above can be executed bythe hardware, or by the software. In the case where the series of piecesof processing described above are execute by the software, the programconstituting that software is installed in the computer. FIG. 26 is ablockdiagram depicting an example of a configuration of hardware of acomputer which executes the series of pieces of processing describedabove in accordance with a program.

In the computer 1000, a Central Processing Unit (CPU) 1001, a Read OnlyMemory (ROM) 1002, and a Random Access Memory (RAM) 1003 are connectedto one another through a bus 1004. An input/output interface 1005 isfurther connected to the bus 1004. An input portion 1006, an outputportion 1007, a recording portion 1008, a communication portion 1009,and a drive 1010 are connected to the input/output interface 1005.

The input portion 1006 is constituted by a keyboard, a mouse, amicrophone, or the like. The output portion 1007 is constituted by adisplay, a speaker, or the like. The recording portion 1008 isconstituted by a hard disc, a nonvolatile memory, or the like. Thecommunication portion 1009 is constituted bya network interface, or thelike. The drive 1010 drives a removable medium 1011 such as a magneticdisc, an optical disc, a magneto-optical disc or a semiconductor memory.

In the computer 1000 configured in the manner as described above, theCPU 1001 loads the program recorded in the ROM 1002 or the recordingportion 1008 into the RAM 1003 through the input/output interface 1005an the bus 1004, and executes the program, thereby executing the seriesof pieces of processing described above.

The program which is to be executed by the computer 1000 (CPU 1001), forexample, can be recorded in the removable medium 1011 as package mediaor the like to be provided. In addition, the program can be providedthrough a wired or wireless transmission medium such as a local areanetwork, the Internet, or digital satellite broadcasting.

In the computer 1000, by mounting the removable medium 1011 to the drive1010, the program can be installed in the recording portion 1008 throughthe input/output interface 1005. In addition, the program can bereceived in the communication portion 1009 through a wired or wirelesstransmission medium, thereby being installed in the recording portion1008. In addition thereto, the program can be installed in the ROM 1002or in the recording portion 1008 in advance.

Here, it should be noted that the pieces of processing which are to beexecuted by the computer in accordance with the program do not need tobe necessarily executed in time series along the order described as theflow chart. Specifically, the pieces of processing which are to beexecuted by the computer in accordance with the program include piecesof processing which are executed in parallel or individually (forexample, the parallel processing or processing by an object). Inaddition, the program may be one which is to be executed by one computer(processor) or may be one which is dispersedly processed by a pluralityof computers.

It should be noted that the embodiment of the present technique is by nomeans limited to the embodiment described above, and various changes canbe made without departing from the subject matter of the presenttechnique.

In addition, the present technique can adopt the followingconstitutions.

(1)

A data processing apparatus, including:

a production portion configured to produce signaling containing a Nullcell number exhibiting the number of Null cells of cells of a sub-frameincluded in a physical layer frame; and

a processing portion configured to process the signaling so as for thesignaling to be included in a preamble of the physical layer frame.

(2)

The data processing apparatus according to (1), in which the Null cellnumber is the number of cells obtained by subtracting an active datacell number exhibiting the number of cells of valid data in thesub-frame from a total data cell number exhibiting the number of allcells in the sub-frame.

(3)

The data processing apparatus according to (1) or (2), in which thesignaling contains first control information, and second controlinformation read out after the first control information, and

the Null cell number is contained either in the first controlinformation or in the second control information.

(4)

The data processing apparatus according to (3), in which one or moresub-frames are included in the physical layer frame,

the Null cell number of a first sub-frame is contained in the firstcontrol information, and

the Null cell number of remaining sub-frames other than the firstsub-frame is contained in the second control information.

(5)

The data processing apparatus according to (3) or (4), in which thefirst control information is smaller in data size than the secondcontrol information, and is transmitted in robuster style than thesecond control information.

(6)

The data processing apparatus according to (2), in which the productionportion produces signaling containing a number of ½ of the active datacell number or the Null cell number instead of the Null cell number.

(7)

The data processing apparatus according to any one of (3) to (5), inwhich the physical layer frame is a physical layer frame prescribed inAdvanced Television Systems Committee (ATSC) 3.0,

the first control information is L1-basic information (L1-Basic)prescribed in ATSC3.0,

the second control information is L1-detailed information (L1-Detail)prescribed in ATSC3.0, and

a sub-frame Boundary Symbol (SBS) as a symbol of a boundary of thesub-frame is contained in the sub-frame.

(8)

A data processing method for a data processing apparatus, including thesteps of:

producing signaling containing a Null cell number exhibiting the numberof Null cells of cells of a sub-frame included in a physical layer frameby the data processing apparatus; and

processing the signaling so as for the signaling to be contained in apreamble of the physical layer frame by the data processing apparatus.

(9)

A data processing apparatus, including:

a processing portion configured to process signaling contained in apreamble of a physical layer frame, and containing a Null cell numberexhibiting the number of Null cells of cells of a sub-frame included inthe physical layer frame.

(10)

The data processing apparatus according to (9), in which the processingportion decodes data, of series of a physical layer, contained in areceived signal transmitted through a transmission path, and deciphersthe Null cell number contained in the signaling.

(11)

The data processing apparatus according to (10), further including

a frequency deinterleaving portion configured to carry out deinterleavein a frequency direction for valid data in response to the Null cellnumber deciphered by the processing portion.

(12)

The data processing apparatus according to (9), in which the Null cellnumber is the number of cells obtained by subtracting an active datacell number exhibiting the number of cells of valid data of thesub-frame from a total data cell number exhibiting the number of allcells of the sub-frame.

(13)

The data processing apparatus according to (9) or (12), in which thesignaling contains first control information, and second controlinformation read out after the first control information, and

the Null cell number is contained either in the first controlinformation or in the second control information.

(14)

The data processing apparatus according to (13), in which one or moresub-frames are included in the physical layer frame,

the Null cell number of a first sub-frame is contained in the firstcontrol information, and

the Null cell number of remaining sub-frames other than the firstsub-frame is contained in the second control information.

(15)

The data processing apparatus according to (13) or (14), in which thefirst control information is smaller in data size than the secondcontrol information, and is transmitted in robuster style than thesecond control information.

(16)

The data processing apparatus according to (12), in which the signalingcontains a number of ½ of the active data cell number or the Null cellnumber instead of the Null cell number, and

the processing portion processes the signaling containing the activedata cell number or a number of ½ of the Null cell number.

(17)

The data processing apparatus according to any one of (13) to (15), inwhich the physical layer frame is a physical layer frame prescribed inATSC3.0,

the first control information is L1-basic information (L1-Basic)prescribed in ATSC3.0,

the second control information is L1-detailed information (L1-Detail)prescribed in ATSC3.0, and

a Sub-frame Boundary Symbol (SBS) as a symbol of a boundary of thesub-frame is contained in the sub-frame.

(18)

A data processing method for a data processing apparatus, including thestep of:

processing signaling contained in a preamble of a physical layer frameand containing a Null cell number exhibiting the number of Null cells ofcells of a sub-frame included in the physical layer frame by the dataprocessing apparatus.

REFERENCE SIGNS LIST

1 . . . Transmission system, 10 . . . Transmission apparatus, 20 . . .Reception apparatus, 40 . . . Transmission path, 111 . . . Encoderportion, 112 Parameter control portion, 113 Error correction encodingportion, 114 . . . Time interleaving portion, 115 . . . Frequencyinterleaving portion, 116 . . . OFDM transmitting portion, 117 . . .Quadrature modulation portion, 118 . . . RF analog portion, 211 . . . RFanalog portion, 212 . . . Quadrature modulation portion, 213 . . . OFDMreceiving portion, 214 . . . Frequency deinterleaving portion, 215 . . .Time deinterleaving portion, 216 . . . Error correction decodingportion, 217 . . . Parameter control portion, 218 . . . Decoder portion,221 . . . Signaling decoding portion, 222 . . . Total data cell numbercalculating portion, 222A . . . ROM (ROM for total data cells), 1000 . .. Computer, 1001 . . . CPU

The invention claimed is:
 1. A data processing apparatus, comprising:circuitry configured to produce signaling containing a Null cell numbercorresponding to a number of Null cells of cells of a sub-frame includedin a physical layer frame, active data cells being arranged between Nullcells, and in frequency, half of the Null cells disposed before theactive data cells and half of the Null cells disposed after the activedata cells; and process the signaling to be included in a preamble ofthe physical layer frame.
 2. The data processing apparatus according toclaim 1, wherein the Null cell number is a number of cells obtained bysubtracting an active data cell number corresponding to a number ofcells of valid data in the sub-frame from a total data cell numbercorresponding to a number of all cells in the sub-frame.
 3. The dataprocessing apparatus according to claim 2, wherein the signalingincludes first control information, and second control informationfollowing the first control information, and the Null cell number isincluded either in the first control information or in the secondcontrol information.
 4. The data processing apparatus according to claim3, wherein one or more sub-frames are included in the physical layerframe, the Null cell number of a first sub-frame is included in thefirst control information, and the Null cell number of remainingsub-frames other than the first sub-frame is included in the secondcontrol information.
 5. The data processing apparatus according to claim4, wherein the first control information is smaller in data size thanthe second control information, and is transmitted in a more robust waythan the second control information.
 6. The data processing apparatusaccording to claim 2, wherein the circuitry produces signaling including½ of the active data cell number or ½ of the Null cell number.
 7. Thedata processing apparatus according to claim 3, wherein the physicallayer frame is a physical layer frame prescribed in Advanced TelevisionSystems Committee (ATSC) 3.0, the first control information is L1-basicinformation (L1-Basic) prescribed in ATSC3.0, the second controlinformation is L1-detailed information (L1-Detail) prescribed inATSC3.0, and a sub-frame Boundary Symbol (SBS) as a symbol of a boundaryof the sub-frame is contained in the sub-frame.
 8. A data processingmethod for a data processing apparatus, comprising: producing, withcircuitry, signaling including a Null cell number corresponding to anumber of Null cells of cells of a sub-frame included in a physicallayer frame, active data cells being arranged between Null cells, and infrequency, half of the Null cells disposed before the active data cellsand half of the Null cells disposed after the active data cells; andprocessing, by the circuitry, the signaling to be included in a preambleof the physical layer frame.
 9. A data processing apparatus, comprising:processing circuitry configured to process signaling included in apreamble of a physical layer frame, the signaling including a Null cellnumber corresponding to a number of Null cells of cells of a sub-frameincluded in the physical layer frame, active data cells being arrangedbetween Null cells, and in frequency, half of the Null cells disposedbefore the active data cells and half of the Null cells disposed afterthe active data cells.
 10. The data processing apparatus according toclaim 9, wherein the processing circuitry is configured to: decode data,of a series of a physical layer, contained in a received signaltransmitted through a transmission path, and to decipher the Null cellnumber included in the signaling.
 11. The data processing apparatusaccording to claim 10, wherein the processing circuitry is furtherconfigured to deinterleave valid data in a frequency direction inresponse to the Null cell number.
 12. The data processing apparatusaccording to claim 9, wherein the Null cell number is a number of cellsobtained by subtracting an active data cell number corresponding to anumber of cells of valid data of the sub-frame from a total data cellnumber corresponding to a number of all cells of the sub-frame.
 13. Thedata processing apparatus according to claim 12, wherein the signalingincludes first control information, and second control informationfollowing the first control information, and the Null cell number isincluded either in the first control information or in the secondcontrol information.
 14. The data processing apparatus according toclaim 13, wherein one or more sub-frames are included in the physicallayer frame, the Null cell number of a first sub-frame is included inthe first control information, and the Null cell number of remainingsub-frames other than the first sub-frame is included in the secondcontrol information.
 15. The data processing apparatus according toclaim 14, wherein the first control information is smaller in data sizethan the second control information, and is transmitted in a more robustway than the second control information.
 16. The data processingapparatus according to claim 12, wherein the signaling includes ½ of theactive data cell number or ½ of the Null cell number, and the processingcircuitry processes the signaling including the active data cell numberor a number of ½ of the Null cell number.
 17. The data processingapparatus according to claim 13, wherein the physical layer frame is aphysical layer frame prescribed in ATSC3.0, the first controlinformation is L1-basic information (L1-Basic) prescribed in ATSC3.0,the second control information is L1-detailed information (L1-Detail)prescribed in ATSC3.0, and a Sub-frame Boundary Symbol (SBS) as a symbolof a boundary of the sub-frame is contained in the sub-frame.
 18. A dataprocessing method for a data processing apparatus, comprising:processing, with circuitry, signaling included in a preamble of aphysical layer frame and including a Null cell number corresponding to anumber of Null cells of cells of a sub-frame included in the physicallayer frame, active data cells being arranged between Null cells, and infrequency, half of the Null cells disposed before the active data cellsand half of the Null cells disposed after the active data cells.